Month: July 2007

Do pesticides contribute to autism?

Here is the latest, excerpt:

Examining three years of birth records and pesticide data, scientists from the Public Health Department determined that the Central Valley women lived within 500 meters, or 547 yards, of fields sprayed with organochlorine pesticides during their first trimester of pregnancy. Eight of them, or 28%, had children with autism. Their rate of autism was six times greater than for mothers who did not live near the fields, the study said.

There is some attempt to look at larger numbers:

The scientists collected records of nearly 300,000 children born in the 19 counties of the Sacramento and San Joaquin river valleys. Of those children, 465 had autism. The scientists then compared the addresses during pregnancy to state records that detailed the location of fields sprayed with several hundred pesticides.  For most pesticides, no unusual numbers of autism cases were found, but the exception was a class of compounds called organochlorines.

I am mostly skeptical.  There are plenty of autistic children, here and abroad, who were never exposed to these chemicals.  Agricultural valleys in California don’t seem to have especially high rates of autism.  Should I believe "you either get autism from your parents, or in some cases, from pesticides"?  Or "pesticides are a potent epigenetic trigger"?  Or should I believe "they found 465 cases out of 300,000 when they should have found many many more.  Reporting of autism is biased in that sample, and the reporting bias is somehow correlated with certain kinds of agricultural activity."?

So far I’m sticking with the latter.  Four points of note: a) the study author is appropriately cautious, b) he does try to adjust for regional diagnosis center, c) I very much wish this study had a map of incidence, and d) is it really so difficult for the author to discuss what it means that the study is restricted to just one part of California?

Baboon metaphysics

In sum, monkey society is governed by the same two general rules that governed the behavior of women in so many 19th-century novels: stay loyal to your relatives (though perhaps at a distance, if they are a social impediment) but also try to ingratiate yourself with the members of high-ranking families.  The two rules interact in interesting ways.  For members of high-ranking matrilines, the rules of kin-based and rank-based attraction reinforce one another, whereas for the members of low-ranking families they counteract.  A member of a high-ranking matriline is attracted to her kin not only because they are members of the same family but also because they are high-ranking.  A member of a low-ranking family may be attracted to her kin, but she is also drawn away from them by her attraction to unrelated, higher-status individuals.  As a result, high-ranking families are often more cohesive than lower-ranking ones.  Or, to paraphrase Tolstoy’s Anna Karenina, all high-ranking families are alike in their cohesiveness, each low-ranking family is cohesive or not, in its own way.

That is from the excellent Baboon Metaphysics: The Evolution of a Social Mind, by Dorothy L. Cheney and Robert M. Seyfarth.

This book also has the best discussion I have seen of the similarities and differences between human speech and animal vocalization, in this case baboon cries.

Tyler on Robin on Tyler on Robin

Here is Robin on Tyler on Robin

I think of Robin as a dominant intellectual presence in my book (can you guess who the other presences are?).  He is the only specific thinker discussed at any length.  That’s conscious choice, not accident.  He also receives part of the dedication at the end.

In some ways I think of the whole book as an (attempted) rebuttal to Robin.  Robin is the rational constructivist, the logical atomist, the reductionist, and the extreme Darwinian.  The Inner Economist is trying to reconcile (modified) economic reasoning and a (modified) version of common sense morality.

But…for the secularist reductionism beckons and seduces.  Imagine an intellectual war with Darwin, Fourier, Comte, early Carnap, David Friedman and millenarian Christian eschatology on one side (that’s my mental image of how Robin maps into the history of ideas), with bits from Henry Sidgwick, Hayek, Quine, and William James on the other side, yet within the framework of modern microeconomics and with ongoing references to the blogosphere.  I am (implicitly) defending gradualism, pluralism, the partial irreduciblity of individual choice, the primacy of civilization, and yes also a certain degree of social artifice.

But can such a defense succeed?

Note that Robin is wrong to suggest I don’t reply to his views.  I paint him
as engaged in a subjective quest — including on bias — rather than standing from an
Archimedean point.  And within the realm of subjective quests, I try to
outline a superior one, especially in the last few chapters of the
book.  He doesn’t like being relativized in this fashion, and that he doesn’t see me as replying to him is itself an indicator of our underlying differences.

Still, I know I have to be afraid of Robin!  Most people who don’t find Robin’s ideas compelling are simply unwilling to face up to the holes in what they believe. 

Wake up, and take at least a sip from the Robin Hanson Kool-Aid.  Life will never be the same again.

And if you can, hire him to write a book for you.

Ingmar Bergman dies at 89

Here is one obituary, here is Wikipedia.  His six-hour Scenes from a Marriage is probably my favorite movie, ever (in the more common abridged version only the first installment makes sense, but it is still a knockout).  The Seventh Seal is his most overrated movie; Wild Strawberries and Fanny and Alexander are also famous but not his best stuff.  The dreamy Persona is the next one to try, or at 83 minutes probably the best introduction to his work.  Winter Light is splendid on a big screen.  Smiles of a Summer Night was my favorite movie in my thirties.  The hilarious Devil’s Eye — a take-off on Faust and Don Giovanni — is the most underrated.  At least twenty of his movies are worth seeing, just dig in and keep going.  I am still sorry I never saw his theatrical production of A Winter’s Tale when it came to NYC.

Equalizing the rate of tax on income and capital gains?

Alan Blinder had a good column yesterday, summarized and discussed by Mark Thoma.  The current movement, supported by Greg Mankiw I might add, is trying to raise the rate of taxation on private equity income so that Warren Buffet is not paying a lower tax rate than someone poorer than me.  More generally, it seems to many people that the rate of taxation on capital gains should be the same as the rate of taxation on ordinary income.

It’s hard to go against the weight of that opinion, but I would like to refocus the debate on the difference between stated and real rates of capital taxation, most of all with regard to loss offsets.  I haven’t seen this discussed in the very recent debates, though it is an old theme in public finance.

My uninformed-by-ever-having-been-a-tax-lawyer sense is that loss offsets for the capital gains tax are worth a great deal to some investors.  Sell your winners to coincide with selling some losers and claim a net gains income of zero or very low.  Let the asset winners ride and they will end up in your bequest and have their taxable values reset upon your death.  If your option values line up the right way, you have enough diversification, and you are not liquidity constrained, it seems that for many people the de facto rate of capital gains taxation is not 15 percent but rather close to zero.  (Maybe not quite zero in expected value terms; it’s tricky because if the losses exceed the gains you can deduct only $3000 of the losses from regular income but on the upside you’re taxed all the way.  On the other hand, you can offset with charitable deductions.)

Let’s say we raised the book rate of tax on capital gains to forty percent.  For some people the net real rate of tax on capital gains could still be zero.  For other people it would be forty percent.

Let’s say we raised the book rate of tax on capital gains to eighty percent.  For some people the net real rate of tax on capital gains could still be zero.  For other people it would be eighty percent.

Under which of these scenarios have we equalized the tax rates on capital gains and labor income?

For any published capital gains rate, it seems there are two or more (and possibly wildly disparate) real rates de facto.  Again, I’m no tax lawyer, but it seems any capital gains tax hike falls disproportionately on the non-diversified (if you hold only one asset and it is a huge winner, where can you get a loss offset from?  The quality of your tax accountant probably matters too.  Any other factors?).

No matter what, capital gains rates for some investors are too high and for others the rates are too low.  And don’t be shocked if many of those "too low" rates are enjoyed by the wealthy.  There will be unfairnesses when compared with income taxation as well.  It is a question of choosing your unfairness, not being able to eliminate unfairness or differential treatment.  So the mere fact that one apparently unjustified unfairness has been pointed out…well…I’m not yet ready to cry uncle.

One reason why the Clinton tax hikes weren’t so bad for capital formation is because capital gains taxes can be avoided in various ways.  The Bush defenders should recognize that and admit that K gains tax hikes are not always a disaster.  On the other hand, the notion of equalizing income and capital gains rates is a myth, and always will be.  There simply isn’t a single capital rate that ends up applied to everyone, no matter what it says on paper.

You might go down another path and talk about eliminating the loss offset.  I wonder if that can be done feasibly.  For instance it would mean that assets A and B, held together in a mutual fund are worth more than assets A and B held separately.  You can think of other problems with this in your spare time.

Yet another (and better) path is to institute a consumption tax, but in the meantime these other kinds of unfairness are not going to disappear.  See also Martin Feldstein on other costs of capital income taxation.

It makes perfect sense to say: "we’ve already spent the money, taxes somewhere have to go up."  But the Buffet example, taken alone, doesn’t convince me much.  Let’s start by taxing negative externalities at a higher level, not by focusing on major creators of wealth.

Dare and Double Dare

Chris Masse writes:


[I’m testing the solidity of the oath taken by the purchasers of
Tyler Cowen’s new book –they had to promise not to give out the URL of
his secret blog to strangers.]

I look forward to Chris’s report…

Addendum: Here is a great post by Kieran.

Taxonomy matters

It is my mission to correctly re-shelve books to the appropriate section of the bookstore. 

For example, "Darwin’s Black Box", the famous psuedo-science book by the non-evolutionary non-scientist Michael Behe,
should not be in the "Evolutionary Biology" section, but something more
appropriate, such as "New Age", "Religion", "Christianity", or even
"Fiction".  You get the idea.

Here is more, and the pointer is from the newlywed Jacqueline Passey.

Assorted links

1. Famous economists ranked by Google Trends

2. Fabio Rojas’s most popular post

3. "Rent-an-American," German style

4. "Feigenbaum did not
actually take the dime out of his briefcase, as it is suspicious to stare
at dimes."

5. Assessment of cap-and-trade proposals

6. Review of Discover Your Inner Economist, from The Washington Post; the reviewer calls it "the most useful of the lot," though he is skeptical about the whole "Freakonomics trend."